FIG. 2.

Comparative maps of the genomes of E. coli phages Rtp (top, 46,219 bp) and T1 (bottom, 48,836 bp). Both phages contain circularly permutated genomes, which are shown with the predicted locations of the pac sites close to the left end. The scale for the T1 genome starts 2 kb to the left of the scale for the genome of Rtp. The T1 map is redrawn to scale from the data presented by Roberts et al. (75). The relative locations of orthologous genes, shown by the dashed lines between the Rtp and T1 genes, reveal a high degree of synteny (see Table 2 for details). Gene numbering is shown above the ORFs. The locations of the HNH endonuclease genes (two genes in Rtp, three genes in T1) are not conserved between the two phages. Gene products: Pnk, polynucleotide kinase; TerS, terminase small subunit; TerL, terminase large subunit; tail tip proteins M, L, K, and I and fiber J, homologs of λ tail assembly proteins; Erf, essential recombination function; Ssb, single-stranded-DNA-binding protein. Regul., regulator.